Catheters for extracorporeal blood purification may be located in various venous locations and cavities throughout the body of a patient for administration of solutes and for removal of toxins and fluids from the body via an extracorporeal blood circulation. Such venous catheterization may be performed by using a single catheter having multiple lumens. A typical example of a multiple lumen catheter is a dual lumen catheter in which one lumen serves to aspirate blood (arterial line) and the other lumen serves to restitute cleaned blood (venous line). An example of such a dual lumen catheter assembly is the SPLIT CATH® catheter, manufactured by Medical Components, Inc. of Harleysville, Pa. Catheterization may also be performed by using separate, single lumen catheters inserted through the same incision into the deep vein to be catheterized. Such dual catheter assemblies are also manufactured by Medical Components, Inc. of Harleysville, Pa. An example of a dual single lumen catheter assembly is the Tesio® catheter system, sold by Medical Components, Inc.
Generally, to insert any catheter into a deep vein or other blood vessel, the vessel is identified by aspiration with a long hollow needle in accordance with the well known Seldinger technique. When blood enters a syringe attached to the needle, indicating that the vessel has been found, a thin guide wire is then introduced, typically through the syringe needle or other introducer device into the interior of the vessel. The introducer device is then removed, leaving the distal end portion of the guide wire that has been inserted into the vessel within the vessel and the opposing proximal end of the guide wire projecting beyond the surface of the skin of the patient. At this point, several options are available to a physician for catheter placement. The simplest option is to pass a semi-rigid catheter into the vessel directly over the guide wire. The guide wire is then removed, leaving the catheter in position within the vessel. If the catheter to be inserted is significantly larger than the guide wire or is constructed from soft, flexible polymer material, a vein dilator device, generally within a sheath, is passed over the guide wire to enlarge the guidewire entrance site and to facilitate the introduction of the catheter. The dilator is removed and the catheter is inserted through the sheath over the guidewire, into the vein. The sheath is then removed, and the guidewire is also then removed, leaving the catheter in place.
For chronic catheterization, in which the catheter is intended to remain inside the patient for an extended period of time, such as for weeks or even months, it is typically desirable to subcutaneously tunnel the catheter into the patient using various tunneling techniques. The proximal end of the catheter may be tunneled after the catheter is inserted into the patient's vein. The subcutaneous tunnel provides a stable anchor to prevent the proximal end of the catheter from moving and possibly becoming dislodged, which could result in patient discomfort and risk of injury, such as infection, inflammation, or accidental withdrawal. Currently available products do not provide a catheter port that facilitates a secure connection with the exit site of the patient. Furthermore, current products do not provide for a compact port for the administration of extracorporeal treatment.
It would be beneficial to provide a catheter port assembly that provides a self-contained flow restricting valve. Additionally, it would be beneficial to provide a catheter port assembly that is adapted to be partially inserted into the exit site of a subcutaneous tunnel, thereby sealing the exit site and retaining the assembly partially within the subcutaneous tunnel through the ingrowth of flesh around the adapter.